John Deere 301a only goes backwards

[somanytractors]

I bought this a couple years ago with this problem and I'm just now getting back around to fixing it.
It works great in reverse but in forward nothing at all.
It doesn't even try.
I'm actually suspect of the valve block because it's cover is leaking a bit. It has a homemade gasket but it looks like it's been working a while since anyone had the cover off judging by the untouched crud build up.
I read something about checking the pressures. I'm guessing the little plugs on top is where I attach a gauge?

I'm not real sure what to look for here.
My plan is to check the pressures, and then probably pull the cover off and pull the valve and check the seals.
If I don't see anything that looks odd, I guess. I'll need to split the tractor and put new clutches and seals in it?
Any help or advice is greatly appreciated!
Thanks
John

 

[Tx Jim]

I suggest to check control linkage at shift control valve for a broken or missing roll pin.

 

[somanytractors]

The linkage is good.
I ran it today and the little leak I mentioned is not little at all. It's spraying a pretty good stream of fluid out around that bolt. I imagine that pressure needs to be inside heading to the forward clutches. I'm going to pull that cover off. It's pretty obvious at this point that something is very wrong in there. I'm guessing a blown o-ring.
Now I'm questioning the homemade gasket. If there's high pressure in there, I wouldn't think a paper gasket would hold up long at all.

I suggest to check control linkage at shift control valve for a broken or missing roll pin.

.

 

[Harry in Ky]

This looks like it might be what you have. Appears to be just a single gasket, no O rings or sealing washers. Probably a bit heavier material than a homemade paper replacement.

 

[Harry in Ky]

https://partscatalog.deere.com/jdrc/sidebyside/equipment/16920/referrer/navigation/pgId/2791587

 

[somanytractors]

https://partscatalog.deere.com/jdrc/sidebyside/equipment/16920/referrer/navigation/pgId/2791587

Thanks so much.
That is very helpful having a blow up of what's supposed to be there, with part numbers even. I was questioning if there should be a gasket or not.
The gasket is definitely shot. It would be nice if that's all that's wrong with it. As much as it's leaking, I cant see how it would still work.

At least now I can take it apart if need be and I have a blow up of how it goes together.
Thanks

 

[Williy]

Make sure you check the fluid level

willy

 

[somanytractors]

So I put a new gasket in and it's still not working.
At this point, I'm inclined to pull the whole block off and get it on the table so I can go through it. I already pulled off the back cover and so far everything looks fine except that part #30 wont come out of it's hole.
So the question is, the pics show what looks like cut outs on the side for fluid or maybe they're just there.
Does the side where the brake housing attaches, and the side where the block attaches to the transmission have gaskets? and is there any balls in those cut outs that are going to fall out and need put back in a certain place?
Thanks
John

 

[Harry in Ky]

Having never worked on a John Deere reverser transmission I have no personal experience to share. I can say this. I would be looking for some pressure test ports to begin with. If that doesn't prove anything, the next step would be to dig into it a little deeper to try and find the pressure passages leading to the individual clutch packs and do some air checks to see if both packs react the same way to air pressure. That will tell you something.

 

[somanytractors]

Having never worked on a John Deere reverser transmission I have no personal experience to share. I can say this. I would be looking for some pressure test ports to begin with. If that doesn't prove anything, the next step would be to dig into it a little deeper to try and find the pressure passages leading to the individual clutch packs and do some air checks to see if both packs react the same way to air pressure. That will tell you something.

Good idea. There is 2 ports on top that I'm pretty sure are for pressure testing. I might just do that, although I'll have to put it back together first. I'm pretty sure I'm going to try that tomorrow. That can quickly rule out the clutch packs. Even if I do pull the valve block all apart it's good to do the testing first so I have a better idea if I'm headed the right way.
Thanks

 

[Harry in Ky]

Pressure testing the clutches doesn't really rule anything out. Depending on where the test ports are located, there could still be internal leaks in the valves or passages leading to the clutches that can cause problems even if both clutches are indeed sound. In my opinion it's a necessary first step, and the results may help point the way to the next step.

In my opinion it would be worthwhile to locate a tech manual that explains the theory of operation and test procedures of at least the hydraulic portion of the transmission.

 

[somanytractors]

I wound up taking the valve block apart. Nothing wrong in there. Not really much to go wrong that would cause the problem it's having, other then a blown gasket, which wasn't the case.
I did check the pressure. reverse port is 150, forward is 0. It's got to be leaking inside.
Can anyone tell me where the clutch packs are? in the tranny, rear end?
I'm looking for a parts diagram but haven't found one yet.

 

[Harry in Ky]

https://partscatalog.deere.com/jdrc/navigation/equipment/16940

Must not be looking very hard

 

[somanytractors]

https://partscatalog.deere.com/jdrc/navigation/equipment/16940

Must not be looking very hard

There's nothing there that shows where the clutch packs are, or anything transmission related. There is pics that show the clutch packs, but not where they go. I did read somewhere that they are between the clutch and transmission, so I guess I'll start there.

 

[Harry in Ky]

If you have no idea where the clutches are, maybe you're past the point of studying parts diagrams. Time to consult a tech manual.

 

[somanytractors]

I finally tore into this.
Turns out the reverser is the entire center housing between the motor and transmission.

It is between the clutch and transmission but it's deceiving because the shifters don't go into the transmission. The transmission is actually in with the rear end.
To work on the reverser you need to take off the cover with the shifters, and then remove the rear end/transmission, and then remove the housing with the reverser from the motor. That whole thing needs to come out.
I took off the shifters and rear end today. And took out the reverser, except it's just one end of it. You cant get to the other end without removing the housing from the motor. They put one set in the front half of the housing and the other set in the rear of the housing so you really need to pull the whole thing. I don't see any bent pipes or anything but it don't matter at this point to put it together without checking the front wouldn't make any sense at all.
Once you get the back off there's not that much more work to removing the whole housing. This design is actually good in a way. When I put it back, I can put the entire reverser together, control block, tubes, and all, and then put the whole unit back in the tractor. Having taken it apart I found that there is a plate behind the control block that comes off (must be removed to get the reverser out of the housing), but removing it if your not taking the reverser out would be a bad idea as it holds all of the tubes in place.
So the easiest way to get this thing apart is remove the cover, remove the rear end, remove the housing with the reverser (valve block and all), and then tear into the reverser.
I added another pic showing the back half of the reverser inside the back of the housing. The tubes mostly run over to the valve block.

EDIT
I pulled it the rest of the way out this morning. Added 2 pics of the reverser out of the tractor.

 

[somanytractors]

The front half of the reverser is messed up. The seal is shot and for whatever reason the clutch pack is digging into the front housing.
I believe it's moving ahead far enough for the oil to escape from behind the clutch pack. I don't see anything else wrong so I'm pretty sure this is the problem. Now to figure out how to fix it.

 

[somanytractors]

Sadly, I've come to the decision to part this one out.
That seal at the front has nothing to do with the hydraulics.
And I've come to the realization that there isn't supposed to be a thrust washer to hold the hub in as the cover is aluminum. Putting pressure on an aluminum housing doesn't seem like something they would do. I'm inclined to believe that the hydraulic pressure in the groove between the metal rings is what keeps it in.
I cant find anything that stands out as the problem, except I did notice that one of the metal rings on the front hub has a large area that looks like it's not coming into contact with the housing and it should be. And then where the ring should be rubbing, there is a lot of wear.
Looks like the kit is about $600 if I can even find one, and that doesn't include the hub that's pretty much obsolete.
I'm not very confident that this is fixable without spending way too much money, and time tracking down parts.
At this point going on with this one just doesn't make sense to me.

 

[Harry in Ky]

I've been following this from a distance, but having never been into one I hesitate to offer any suggestions. I found what I believe is the shaft assembly in your photo in the parts book (R39084) but I can't find the aluminum housing. I may have some books on similar model utility tractors that cover the reverser transmission. I need to look into that as I'm not sure how all that fits together. I don't see how the flange pictured can contact the housing unless the splined end has lost support from whatever it rides on/against. Maybe something in that area is allowing the shaft to travel too far forward? That may account for the contact and scoring, but does that have any affect on the pressure to the forward clutch pack? Not sure on that part.

 

[somanytractors]

I've been following this from a distance, but having never been into one I hesitate to offer any suggestions. I found what I believe is the shaft assembly in your photo in the parts book (R39084) but I can't find the aluminum housing. I may have some books on similar model utility tractors that cover the reverser transmission. I need to look into that as I'm not sure how all that fits together. I don't see how the flange pictured can contact the housing unless the splined end has lost support from whatever it rides on/against. Maybe something in that area is allowing the shaft to travel too far forward? That may account for the contact and scoring, but does that have any affect on the pressure to the forward clutch pack? Not sure on that part.

Thanks
I'll get some pics in a couple days.
I looked at it again this morning after posting.
There's really nothing that keeps it in. Unless it's the pilot bearing but that would be pretty weird.
I really believe the hydraulic pressure keeps it in which would also be weird but there is nothing else.
Nothing has a groove for a snap ring. The back of the clutch hub just slides into the casing and nothing holds it there.
There is a shaft that goes through the hub, but again no grooves for snap rings or anything.

It's actually not the hub that's worn.
The 2 metal rings are in the hub and they don't look right but they are cheap and easy to replace.
The part where they rub is the biggest problem. It's an insert in the housing. Looking at it, it's pretty badly worn and I'm sure it has to be leaking a lot. It could maybe be replaced but I would have to find one and then probably take it to the machine shop to get it replaced. It's not in an easy place to get to.
I dont think the damage to the front cover is effecting it at all. I think it's not working because the hub is coming out far enough that the pressure is escaping past the rings, including the back ring so it's getting behind the clutch pack and pushing it forward into the front cover which is probably why it's not working and why the cover is damaged.
I will get some pics of it all in a couple days and share them here for anyone that needs the info in the future.